Investigation of Transient Two-Phase Flow during Refrigeration and Air Conditioning System Startup

Hendrick, M.J.; Jassim, E.W.; Newell, T.A.

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https://hdl.handle.net/2142/12914 Copy

Description

Title

Investigation of Transient Two-Phase Flow during Refrigeration and Air Conditioning System Startup

Author(s)

• Hendrick, M.J.
• Jassim, E.W.
• Newell, T.A.

Issue Date

2006-12

Keyword(s)

• two-phase flow
• air conditioning system startup

Abstract

The purpose of this investigation is to develop models for transient slug flow under refrigeration system startup conditions. Slug flow is generated for two-phase air-water and R134a with pressure differences of 69-520 kPa; slug volumes of 40-400 ml; and 6.35, 10.2, and 13.4 mm tube diameters under high and low pressure side conditions. Flow visualization images are recorded with a high speed camera and digital web camera. A film thickness sensor design is described for use in the once through flow loop. The trends of the film thickness sensor output, pressure difference, slug location, and slug breakdown distance are discussed. Four separate models are generated to describe the slug acceleration and breakdown. The models are compared to experimental data and simplified further. The simplified model predicts the acceleration and breakdown of the slug with four inputs: fluid, applied pressure difference, slug volume, and tube diameter. The performance and uncertainty of the model are discussed. Models are also generated to determine the tube length required for slug breakdown.

Publisher

Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Air Conditioning and Refrigeration Center TR-254

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/12914

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Project 200

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